Average Daily Census is a Myth

The old joke about how even a broken clock is right two times a day has a lesson for hospitals — and in particular, one of the time-honored metrics they use.

The average daily census (ADC) is derived by taking an average across all times of the day and night — numbers that often vary greatly.

The ADC is one of the core metrics a hospital uses to quantify its operations when seeking JCAHO accreditation, among other things. In addition, hospital administrators commonly use their ADC to understand the size, needs and other aspects of the inpatient population. Reported monthly, the number can be used for financial reporting, calculating average length of stay, and driving various management decisions.

Hospitals track ADC to support a number of different needs, including budget planning and financial reporting. The problem with tracking ADC? It undercounts census for a good part of every day. As a result, managers making daily operational decisions and planners looking to the future lack insight into real levels of patient need for beds.

Where ADC comes up short

In most hospitals, patients are coming and going all the time. There is generally a noticeable increase in the patient population between noon and 5 or 6 PM. This spike includes patients who are getting ready to be discharged, as well as a ramp-up in admitted emergency department patients.

In addition, most of the day’s surgeries are complete, and as those patients are completing their stay in the Post Anesthesia Care Unit, they will need to be moved to a hospital bed. There are also a number of patients who have been admitted as inpatients by their primary care physicians, either through the emergency department or directly to an inpatient bed.

In short, there’s a flurry of activity from 12 to 5. For example, out of 100 patients in beds during this period, there could be 20 who are about to be discharged and an additional 30 more who are being admitted in one manner or another. Unless current patients are discharged before the new ones are admitted, there can often be a 20-30% spike in daily census during this time. Knowing this number can be exceedingly more valuable in finding bottlenecks downstream and in planning for future needs more accurately.

Most of the hospitals with which my company consults have daily “huddles” in the early morning and mid afternoon to assess inpatient bed counts. In these meetings, each unit manager shares data on how many patients he or she has leaving and arriving. Then they negotiate as a group over which patients will stay where they are, and which must be relocated. In the AM meeting, the focus is preemptive, while in the PM, it’s more about looking at the existing situation and trying to find places for patients.

Is there a better approach?

Ultimately, choosing which metrics you use depends on your purpose. For administrators who want to understand if they’re maintaining their patient population and how they’re managing staffing and budgets, it’s probably appropriate to track both census numbers – the ones for 12 AM and 3 PM.

But when I’m working with FreemanWhite clients, my experience is that the 3 PM census is generally a more useful measure for determining whether there is appropriate capacity, either at the unit, bed type, or hospital level. I typically look at 3 PM census as a histogram, and it allows me to arrive at a 95% confidence level that there’s going to be a certain number of beds. That’s a level of insight and clarity that the ADC simply isn’t designed to provide.

ABOUT THE AUTHOR Delia Caldwell MBADelia Caldwell works with clinical staff to put the systems and processes in place they need to improve care and save lives. Through simulation modeling, process mapping, and dashboard tools she helps departments reduce LOS, improve patient outcomes, and streamline operations. A skilled facilitator, Delia guides organizations through change, using data to demonstrate that her recommendations will improve productivity and efficiency. With more than 85 operational studies completed, her efforts have redefined the way that providers deliver care. Read more from Delia.